using System;

using System.Linq;

public class Program

{

    private static int g(string q, int w)

    {

        return q.Aggregate(new{b=1,c=w,x=1},(l,o)=>l.x<0?l:o=='W'?new{b=1,c=l.c+l.b,x=1}:new{b=l.b*2,c=l.c-l.b,x=l.c-l.b-l.b*2}).c;

    }

    public static void Main()

    {

        L(g("LLLWLLLL", 15));

        L(g("WWWWWLLLLLLLLLWWWWWWWWWWW", 15));

        L(g("LLLWWWWW", 15));

        L(g("LLLWWWWLLWWLWWWWLWWLLLWWWLWWLLLLWLLWWLLLWWWWWLWLWLWWLLLWLWLWLWLWLWLWWLLLW", 15));

        /* Expected output:

        1

        5

        20

        53

        */

    }

    private static void L(object l) {

        Console.WriteLine(l);

    }

}